Assembly for sorting articles by weight



March 25, 1969 P. E. SEABORN E AL 3,434,595

ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Sheet Filed Nov. 20, 1965 T- I [3 q- 1 t m, Wag

INVENTORS PAUL E. SEABORN WENDELL S. THOMPSON BY M0 99 ATTORNEY March 25, 1969 P. E. SEABORN ET AL 3,434,595

ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Filed Nov. 20, 1963 Sheet 5 of 10 I TIE-1.37

INVENTORS PAUL E. SEABORN WENDELL S. THOMPSON ATTORNEY March 25, 1969 P. E. SEABORN ET AL ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Sheet 6 of 10 Filed NOV. 20, 1963 A'I'I'ORNEY March 25 1969 E SEABQRN ET AL 3,434,595

ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Sheet Filed Nov. 20, 1963 P9 wN.

ATTORNEY March 25, 1969 P. E. SEABORN ET AL 3,434,595

ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Filed Nov. 20, 1963 Sheet 8 of 10 INVENTORS PAULv E. SEABORN weuoeu. s. THOMPSON BY Afr /W ATTORNEY March 25, 1969 P. E. SEABORN ET AL 3,434,595

ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Filed Nov. 20, 1963 7 Sheet 9 of 10 INVENTORS PAUL E. SEABORN WENDELL S. THOMPSON ATTORNEY I March 25, 1969 SEABORN ET AL 7 3,434,595

ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Filed Nov. 20, 1963 Sheet 10 of 10 '208 '9 Q1 I g 58 'I8QJ L llllll '12 INVENTORS PAUL E. SEABORN 4 WENDELL S. THOMPSON ATTORNEY United States Patent 3,434,595 ASSEMBLY FOR SORTING ARTICLES BY WEIGHT Paul E. Seaborn, Los Gatos, and Wendell S. Thompson,

Saratoga, Calif., assignors to FMC Corporation, San

Jose, Calif., a corporation of Delaware Filed Nov. 20, 1963, Ser. No. 325,097 Int. Cl. B07c 5/16; B07!) 13/08 US. Cl. 209121 12 Claims The present invention relates to the sorting of articles in general, and more particularly to apparatus for continuously sorting a succession of articles on the basis of their weight.

The sorting assembly of the present invention includes a scale, commonly referred to as a checkweigher, which continuously receives a succession of articles, measures their Weight, and passes them on to a reject assembly or deflector. The reject assembly is remotely controlled in accordance with the weight of a previously weighed article, and it either accepts or rejects the article, depend ent upon its weight relative to a predetermined standard. In the present invention, the scale and reject unit are rigidly connected, and are pivotally mounted as a unit on a base, so that the articles merely slide down across the sloping assembly.

An object of the present invention is to provide a quickly responsive scale or checkweigher which can accurately weigh a succession of articles moving at high speed across the scale. This is accomplished by providing a light weight (low mass) scale platform, in combination with a sensitive, low mass combined weighing and preload spring for the scale platform.

Another object of the invention is to eliminate rocking and bouncing of the articles or containers (such as filled tin cans), as they pass over the scale platform.

It is also an object to cause the article being weighed to remain balanced by two point support or line contact on a single runner scale platform during the weighing operation.

A further object is to provide increased sensitivity of the scale platform, byfieliminating the need for transport belts, particularly belts that pass across the scale platform. This also eliminates drift in weight measurements that occurs during operation of belt transport checkweighers, due to progressive changes in belt tension, and changes in belt characteristics. The necessity for changing belts is also eliminated with the assembly of the present invention.

It is an object of the present invention to provide an assembly of the type described wherein the scale platform does not readily pick up foreign matter such as dirt, food, or liquids (which would throw off the weight measurement), and when necessary, is easy to clean. These advantages are particularly useful when the unit is used in the food packing industry, or in similar industries.

A further object of the invention is to provide a simple slide reject or deflector which cooperates with the scale platform to receive weighed articles smoothly and without bounce of the articles.

Another object is to provide a deflector arm which can be advanced by a rotary solenoid against a stop, with the impact of the deflected articles urging the arm against the stop.

It is an object to provide an assembly of the type described which can be mounted in an inclined position, to facilitate progress of the articles across the assembly, and with the inclination of the assembly being adjustable so that the optimum angle for container handling and transport may be set up for any given installation.

It is also an object of the present invention to provide a unit of the type described which is simple in construction and economical to manufacture.

Briefly, in accordance with the present invention, the scale or checkweigher is provided with a low mass scale platform in the form of a single vertically disposed plate or runner, the upper edge of which is a prolongation of an approach platform forming the upper portion of the scale housing. Guide rails are mounted on each side of the approach platform and the scale platform or runner, and steady the articles such as cans, until they pass across the scale. The guide rails are relieved at the scale run ner, so that the articles are balanced on the runner during weighing. The transport of the articles across the scale platform is accomplished without bounce or vibration of the articles on the scale platform. A slide reject or deflector assembly is mounted on the scale housing, and includes a slide plate which lies substantially in the plane of the approach platform and the upper edge of the scale platform runner. plate, and which is notched to receive the scale platform runner plate. This provides for smooth transfer of the articles from the scale platform to the slide reject or deflector assembly. A combination of a light-weight single runner scale platform of the vertical plate type, and a light weight scale platform suspension including a triangular, light weight combined preload and weighing spring, provides the features of accuracy, sensitivity, and simplicity referred to above.

The manner in which these and other objects of the present invention may be attained by those skilled in the art will be apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings.

In the drawings,

FIGURE 1 is a side elevation of a sorting apparatus including a scale and slide reject or deflector assembly, adjusted to its position of minimum inclination from the horizontal. The position of maximum inclination of the assembly is partially shown in phantom lines in FIG- URE l.

FIGURE 2 is a plan of the scale assembly with the slide reject or deflector removed.

FIGURE 3 is a section taken on lines 3-3 of FIG. 2.

FIGURE 4 is a side elevation of the scale assembly, with the cover plate removed and parts in section.

FIGURE 5 is a vertical section of the scale assembly taken on lines 5 5 of FIGURE 4, and showing the side rail mounting.

FIGURE 6 is a vertical section of the scale assembly taken on lines 66 of FIGURE 4, showing the mounting of the ribs forming the approach platform.

FIGURE 7 is a vertical section of the scale assembly taken on lines 7-7 of FIGURE 4, showing the combined preload and weighing spring adjusting shaft and gearing.

FIGURE 8 is a vertical section of the scale assembly taken on lines 88 of FIGURE 4, showing the weighing spring adjusting control shaft and gearing.

FIGURE 9 is a horizontal section taken on lines 9-9 of FIGURE 4, showing the weighing spring reduction gearing train.

FIGURE 10 is a vertical section taken on lines 10-10 of FIGURE -4, showing the scale platform magnet.

FIGURE 11 is a horizontal section taken on lines 11- 11 of FIGURE 4, showing the combined weighing and preload spring shape, with the spring partially in phantom, and also showing the scale magnet and reed switch assembly.

FIGURE 12 is an enlarged plan view of the slide deflector or reject assembly mounted at the delivery end of the scale.

FIGURE 13 is a side elevation of the slide deflector at the delivery end of the scale, with parts broken away.

FIGURE 14 is an end elevation of the slide deflector or reject assembly at the delivery end of the scale.

Referring to FIGURE 1, a general description of the sorting apparatus of the present invention will first be presented. The unit includes a base indicated generally at 10, which has legs 12 from which projects a vertical post 14. Surrounding the post 14 is a sleeve 16 which mounts the unitary scale and slide reject assembly. The sleeve is vertically adjustable on the post 14, and can be clamped in the adjusted position by clamp bolts 18. At the top of the sleeve 16, ears 20 are provoided for pivotally mounting a rigid assembly of a scale S, and a slide reject or deflector assembly D. This rigid assembly of the scale and reject units is pivotally mounted on the ears 20 by means of a bracket 21 bolted to scale S, and a pivot bolt 22.

The scale and reject assembly is mounted on the base so that the article transporting surfaces thereof are inclined from the horizontal. In the embodiment of the invention shown, the minimum inclination from the horizontal is 10 degrees, and the maximum inclination is 30 degrees. Means are provided for rapid and ready adjustment of the aforesaid angle of inclination of the assembly. This adjustment includes ears 24 mounted on the sleeve 16, which carry a threaded eyebolt 26 by means of a pivot bolt 28. Similar ears 30 are mounted on the under portion of the receiving end of the scale S, and these cars mount a second threaded eyebolt 32 by means of a pivot bolt 34. The threads on the eyebolts 26 and 32 are of opposite hand, and an internally threaded adjusting sleeve 36 is threaded upon the eyebolts, and clamped in adjusted position by a lock nut 38. With this construction, rotation of the sleeve 36 in one direction increases the inclination of the assembly from the horizontal, and vice versa.

The scale S includes a housing 40, the upper portion of which carries an approach platform 42. The scale also includes a scale platform indicated generally at 44, which is in the form of a vertical plate-like member forming a single runner. Guide rails 46 are mounted on the housing at each side of the approach platform 42 and the scale platform 44, to steady articles such as cans K, as they pass across the unit.

The slide reject or deflector assembly D includes a slide plate 50, the upper surface of which is slightly below I the plane of the approach platform 42, and is also slightly below the upper edge of the scale platform 44 when the latter isundeflected. The deflector assembly is mounted on the scale housing 40 by means of a support bracket assembly indicated generally at 52. A deflector arm 56 is pivotally mounted on the deflector assembly, under control of-a rotary solenoid of conventional construction, indicated generally at 58. Articles are supplied to the scale S by means of a feed conveyor 60, the details of which form no part of the present invention, and acceptable articles are received from the deflector assembly D by means of a take-away conveyor 62, or by a chute or bin. There may also be a take-away conveyor, chute, or a bin for receiving rejected articles.

As .the articles such as cans K pass over the scale platform 44, their weight is quickly determined, and electric weight signals are generated for the operation of the rotary solenoid 58, and the deflector arm 56, in case the articles are to be rejected. An article detector or sensor means, shown in phantom at 59, may be interposed between the deflector arm 56 and the scale platform 44 for triggering the deflector arm solenoid 58 at the proper time. The device 59 may be an influence magnetic's-witch, and it can be close to the cans being weighed because of the precise positioning of the articles by rails 46. Details of the weight signal producing circuit, the sensing means 59, and the control circuit form no part of the present invention, and so are not illustrated and described. The reject circuit may be of the general type disclosed and claimed in the copending application of Seaborn, Ser. No. 301,498, filed Aug. 12, 1963, and assigned to the assignee of the present invention, but the present invention is not limited to the use of that circuit.

A detailed description of the scale or check-weigher S will now be provided, particularly with reference to FIGS. 2-11. The scale housing 40 is formed of a box-like member open at the sides, which are covered with side plates 72. Member 70 includes a top plate portion 74, which mounts the approach platform 42. The approach platform 42 includes three longitudinally extending ribs or runners 76 (FIGS. 2, 5 and 6), which are mounted on spacer blocks 78 by means of horizontal clamp bolts 80. The spacer blocks are secured to the top plate 74 of the scale housing 40 by means of bolts 82.

The guide rails 46 are mounted on the top plate 74 of the scale housing at each side of the approach platform 42 and the scale platform 44. In order to mount the guide rails, posts 86, in the form of bolts, are threaded into projecting flanges on the top plate 74, as best seen in FIG. 5. Lower spacing sleeves 88 are slipped over the posts, and the lower guide rails 46 carrying slotted ears 92 rest on the lower spacing sleeves. Upper spacing sleeves 94 rest on the ears 92 of the lower guide rails 46, and the upper guide rails 46 have slotted ears 92 that are clamped between the heads of the bolts 86 and the upper sleeves 94. As seen in FIGURES 2 and 3, the guide rails 46 are machined back or relieved somewhat at 96 (FIGURE 2) by a distance d to clear both sides of the cans or other articles being weighed during the actual weighing operation.

The construction details of the scale platform 44 are best seen in FIGURES 2, 3 and 4. The scale platform comprises a single runner plate 100 having a webbed body and a beaded edge, as best seen in the partial section of FIG. 3. The runner plate 100 is milled from a sheet of steel and its upper edge is flame hardened. When undeflected, the upper edge of the scale platform runner plate 100 forms a continuation or prolongation of the central runner 76 of the approach platform, as best seen in FIG. 4. The scale platform runner plate 100 is screwed to an aluminum support plug 102 by means of capscrews 104. Thesupport plug 102 is clamped against an aluminum cylindrical tubular spacer 106, which projects through an aperture 107 formed in the associated end wall of the housing box member 70. The inner end of the spacer 106 is clamped against an aluminum end support plate 108, by means of a clamp bolt 110. By making these parts of the scale platform assembly of light weight metal, such as aluminum, and by the use of a single thin runner plate, a low mass assembly for providing sensitive weighing action is provided.

The support plate 108 for the scale platform 44 is mounted in the housing 40 by means which freely accommodate vertical motion (i.e., motion perpendicular to the plane of the approach platform 42) of the scale platform 44 relative to the housing, yet position it firmly against longitudinal motion, i.e., motion in the plane of the motion of articles across the scale. Likewise, a long life, sensitive, combined weighing and preload spring is provided which supports the weighing platform vertically during the weighing operation. As best seen in FIG. 4 and in other figures, the scale platform mounting assembly includes an inner frame 112 secured by bolts 114 to the bottom of the box member 70 of the housing 40. The scale platform assembly is restrained from longitudinal motion by upper and lower cantilever springs 116. These springs are formed of chrome-nickel steel, and in the device being described are aproximately of an inch thick, 6 inches long, and approximately 2 /2 inches wide. The inner ends of the cantilever springs 116 are secured to the top and bottom of frame 112 by means of cap plates 118 and cap screws 120, as best seen in FIG. 4. Both ends of the cantilever springs are transversely grooved at 122, to increase their flexibility. As illustrated, these springs are formed of a single sheet of metal and grooved, this construction being claimed specifically in the aforesaid copending application.

The plate 108 of the scale platform assembly 44 is mounted on the forward ends of the cantilever springs 116 by means of cap plates 124 and cap screws 126, thereby restraining the scale platform for all motion other than the weighing motion. A corrugated rubber sealing boot 128 is mounted between the spacer sleeve 106 of the scale platform assembly, and the wall of aperture 107 in the end plate of the box member 70 of the scale housing, to exclude food and other foreign matter from entering the scale housing.

As mentioned, in order to take full advantage of the lightweight characteristics of the single runner scale platform 100' of the present invention, the preload spring must also be of light weight and sensitive construction. In accordance with this concept the' preload spring 130, which also performs the functions of the weighing spring, is triangular in shape (FIG, 11) and is formed of the same material as that of the cantilever springs, namely A inch thick chrome-nickel steel. The base of the preload spring 130 is secured to an adjusting shaft 132, pivotally mounted in the frame 112, with a cap plate and cap screws as described in connection with the mounting of the cantilever springs 116. The apex of the preload spring 130 is mounted by means of nuts 134 on a vertical wire 136, which extends downwardly to a post 138 mounted in the support plate 108 of the scale platform assembly. The wire 136 is silver soldered in the post 138. The preload spring 130 is adjusted to urge the scale platform 44 upwardly, until a stop lug 140 on the support plate 108 engages the bottom of the inner frame 112.

As mentioned, means are provided to adjust or select the degree of preload imparted to the scale platform assembly 44. The adjustment includes a sector gear 142 which projects downwardly from the shaft 132 that mounts the base of the preload spring 130 (FIGS. 4 and 7-9). A first countershaft 14 4 is mounted in the frame 112, and rotatably mounted thereon is a cluster gear 146, the pinion of which is meshed with the sector gear 142. Also mounted in the frame 112 is an adjusting knob countershaft 147. A series of meshing cluster gears 148 are rotatively mounted on shafts 144, 147 (FIG. 9) and each gear includes a pinion and a large gear. These gears are interfitted to provide a gear reduction in the preload adjustment. As seen in FIGS. 7 and 9, an end cluster gear 150, rotatable on shaft 144, meshes with an end gear 152 which is retained on the knob shaft 147 by means of a set screw. Shaft 147 projects through the scale housing, and mounted on the outer end thereof is an adjusting knob 1'54. Rotation of the knob 154, through the gear reduction assembly just described, provides a very delicate adjustment of the preload force on the scale platform. This adjustment is not part of the present invention, and the details thereof are more fully described, and are broadly claimed in the aforesaid copending application.

Means are provided in the scale S to sense the vertical position of the scale platform 44, in order that weight measurement signals can be provided. As seen in FIGS. 4 and 11, a leaf spring switch mounting bracket 160 is secured to the bottom of frame 112 in the scale housing 40. The bracket is vertically adjusted by means of an adjustable position stop bolt 162, the lower end of which engages the bottom of the frame 112. Mounted at the forward end of the bracket 160 is a reed switch 164, this switch being of the type that is closed by the action of magnetic force when a magnet confronts the switch. The reed switch also has a resetting coil (not shown) and the four leads from the switch go to a terminal board 165, as seen in FIG. 11, for connection to the control circuit. In order that the scale platform can operate the reed switch 164 in accordance with its vertical position, a magnet mounting strap 168 is secured to the end support plate 108, as best seen in FIGS.

and 11, and mounted on the strap is a permanent magnet 170, which is in confronting relation to the reed switch 164.

As previously mentioned, details of the control mechanism whereby a reject signal represented by failure of the magnet 170 to close the reed switch 164 when underweight articles have been weighed, form no part of the present invention, and hence are not described in detail. Any suitable circuit of the digital or relay type, controlled by reed switch 164 may be applied. A reject circuit suitable for this service, which also includes an article sensing means in the form of a photocell for triggering the reject deflector, is described in detail in the aforesaid copending application, and is claimed therein. It is understood that under the present invention, the scale platform position sensing means need not be a magnetically operated reed switch. Any position detector such as a linear control differential transformer, or the like, could be substituted for the magnetically operated reed switch assembly described, without affecting the mode of operation of the scale of the present invention.

Details of the slide reject or deflector assembly D appear in FIGS. 12-14 of the drawings. The assembly includes a slide in the form of a plate 50, previously described, the upper surface of which is slightly below the upper edge of the single runner plate of the scale platform 44. The slide plate 50 is rigidly mounted on the scale S by means of the bracket assembly 52, previously mentioned, which bracket assembly includes laterally spaced brackets 176, 178. These brackets adjustably support the slide plate 50 by means of screws 180. The lower ends of the brackets 176, 178 are bolted to the pivot bracket 21 on the scale, by means of bolts 182, as best seen in FIGURE 13. The slide plate 50 has a pass section 184 for articles that are up to weight. Upper edge of plate 50 is slightly below the undeflected scale platform runner plate 100, as previously described. The slide plate 50 is also formed with a reject section 186, in the form of a wing that is bent down along a line of bend indicated at 188 in FIG. 12. The angle of wing section 186 is also shown in FIG. 14. The slide plate 50 also has a slightly bent down lead-in section 190, as best seen in FIGS. 12 and 13.

In order to reject underweight articles or cans, such as a can K1, the deflector arm 56, previously mentioned, is pivotally mounted on the slide plate 50. The deflector arm has a side face 194 (FIG. 12) aligned with the associated guide rails 46. The deflector arm 56 is also formed with a beveled article deflecting nose 196 so that when the arm is rotated to the reject position, as indicated in phantom in FIG. 12, underweight cans such as can K1 will glide along the nose 196 of the deflector arm and will be deflected along the wing section 186, and onto the reject chute, bin or conveyor.

The deflector arm 56 is pinned to a shaft 198 which projects upwardly from the armature 199 of the rotary solenoid 58, previously mentioned. The field coil 200 of the rotary solenoid is fixed to a dust case 202, the upper portion of which is connected to a mounting plate 204. The slide plate 50 is slotted as at 205 (FIG. 12) for receiving clamp bolts 206 that are threaded into the rotary solenoid mounting plate 204, and is also slotted at 205a, to receive the neck of the solenoid dust case 202. This permits adjustment of the deflector arm and solenoid assembly laterally of the plate 50, to accommodate for variations in can or article width, just as the guide rails 46 are adjusted for the same reason.

In order to limit the pivotal motion of the deflector arm 56, a stop bracket 208 is adjustably mounted in a slot 209 formed in the slide plate 50, and clamped by bolts 210. The stop bracket 208 carries an adjustably mounted stop screw 212 which is engaged by a beveled rearward face 214 formed on the deflector arm 56, as best seen in FIG. 12. With this design, impact of the rejected cans K1 is taken by the stop, and need not be withstood by the solenoid which only need flip the deflector arm out to the reject position. The nose 196 of the deflecor arm quickly diverts the cans, backed up by the stop screw 212, as described.

As previously mentioned, if desired an optical, magnetic, or other form of article sensor 59, indicated in phantom in FIGS. 1 and 12, may be provided for triggering operation of the rotary solenoid 58, when a reject signal has been provided, and when the underweight can approaches the sensor device. The details of the sensor device and associated circuitry are not part of the present invention, and therefore are not illustrated or described.

The operation of the sorting assembly of the present invention will be apparent from the previous detailed description thereof, and hence need only be briefly summarized. The angle of inclination of the sorting assembly, illustrated in FIG. 1, is adjusted between the ranges of minimum to 30 maximum, depending upon the conditions of operation and the nature of the articles being inspected. The articles are given a suitable velocity and momentum by the feed device 60, to carry them completely across the scale S and the deflector or reject unit D. The articles first pass along the approach platform 42 where they are guided and steadied by the guide rails 46, so that they assume a steady forward motion. When the articles, such as cans K, reach the single runner plate 100 of the scale platform 44, each article will be supported centrally by the scale platform runner 100, and it will be balanced on the platform and will clear the guide rails 46 on both sides, because of the small offset distance d (FIG. 2 of the drawings). This provides a two point or a line support for the articles on the scale runner plate 100 during weighing, so that the articles exert very little friction force on the scale platform.

The offset distance d can be as small as of an inch, without causing drag on the articles. Thus even though the scale platform is cantilever mounted, it is not disturbed by the mere fact that articles pass across it, but only by their weight. The elapsed time during weighing is so short that the articles remain clear of the side rails 46 on each side, even though the articles may be laterally unbalanced. Thus the scale platform, due to its light weight and due to the sensitive low mass mounting thereof, quickly assumes a position representing the true weight of each article. After the articles have been weighed and start to leave the scale platform, they slide smoothly onto the slide plate 50 of the deflector assembly D, which is notched to surround the terminal part of the runner 100. If the articles are underweight, the weight signals will have been stored, and the deflector arm 56 will be pivoted to the phantom position of FIG. 12, whereupon underweight articles such as can K1, are deflected onto the reject wing 186 of the deflector slide plate 50. As soon as an article leaves the scale platform runner 100, the scale platform 44 immediately returns to its upper position, under the force of the preload weighing spring 130, and comes to rest with the stop lug 140 (FIG. 4) engaging the frame 112 in the scale housing. This use of a definite preload force on the scale platform, which must first be overcome before the scale platform is depressed from its uppermost position, reduces flutter and increases the rapidity of action and sensitivity of the scale.

Since the cans remains balanced on the runner 100 as described, a sensor device of the magnetic proximity type can be placed close to the cans, without touching them as they pass.

With the assembly of the present invention, articles such as No. 303 tin cans of food can be inspected at the rate of 300 cans per minute, spaced by one foot, center to center.

Having completed a detailed description of the present invention so that those skilled in the art may practice the same, we claim:

1. An article sorting assembly comprising a base, a scale housing, an approach platform on the upper portion of said scale housing, a scale platform, a generally triangular preload spring, means mounting the base of said preload spring in said scale housing, means for supporting said scale platform on the apex of said preload spring, scale platform locating means comprising upper and lower cantilever springs being rigidly mounted in said scale housing and with the scale platform being rigidly connected to the outer ends of said cantilever springs, said scale platform comprising a runner plate disposed in the midplane of said approach platform and with the upper edge of said runner plate substantially forming a continuation of said approach platform, guide rails at each side of said platforms, a slide plate rigidly mounted on scale housing and lying substantially in the plane of said platforms, said slide plate being notched to receive said scale platform runner plate, article deflecting means on said slide plate, and means for pivotally mounting said scale housing on said base.

2. A scale for weighing articles of uniform width comprising a housing, longitudinally extending approach and scale platforms on said housing, said platforms being substantially normally coplanar and inclined downwardly from the horizontal, preload spring means connected between said housing and said scale platform, means for restraining said scale platform against longitudinal motion relative to said housing while freely accommodating motion of said scale platform in a plane normal to that of said approach platform, said scale platform comprising a longitudinally extending, narrow single runner in the vertical midplane of the scale, for directly supportingthe articles as they slide across the scale platform, and laterally spaced guide rail means extending along each side of said approach and scale platforms, the lateral spacing of said guide rail means at said approach platform substantially equaling the lateral dimension of the articles for steadying the articles as they pass along said approach platform before the articles slide along the scale platform, the lateral spacing of said guide rail means at said scale platform being slightly greater than the width of the articles, so that articles which were steadied on said approach platform are balanced on the single runner of said scale platform as they slide along the scale platform runner, without touching the scale platform guide rails means.

3. The scale of claim 2, wherein said approach platform has a plurality of, but no more than three, longitudinally extending, laterally spaced, upstanding coplanar ribs for directly supporting the articles to be weighed as they slide to the scale platform.

4. An article sorting assembly comprising a scale housing, an approach platform on the upper portion of said scale housing, a scale platform comprising a single, narrow, article supporting runner bla'de mounted on said scale housing and substantially forming a continuation of said approach platform, a slide reject plate having an article receiving portion forming a longitudinally extending, flat article receiving surface, said surface substantially forming a smooth continuation of the upper edge of said scale platform runner blade, said slide reject plate also having a wing portion extending laterally and downwardly from the article receiving surface of the plate for receiving articles directly as they slide laterally off said one portion of the plate, and article deflecting means at said slide reject plate at the side of said article receiving portion remote from said wing portion; said approach platform, said scale platform runner blade and the flat article receiving surface of said slide reject plate being inclined longitudinally down-wardly for gravity feed of articles along the approach platform, the scale platform runner blade and the slide reject plate.

5. A scale comprising a substantially closed housing, longitudinal coplanar approach and scale platforms on said housing, said platforms being inclined downwardly from the horizontal, said housing having an apertured, generally vertical end wall at said scale platform, scale platform mounting means comprising a depending member, a mounting bracket rigidly connected to said depending member and projecting longitudinally through the end wall aperture of said housing, means between said scale platform mounting means and said housing end wall 'for sealing off said aperturewhile freely accommodating motion'of said scale platform relative to said housing, spring means in said housing connected between said housing and said scale platform mounting bracket for yieldably supporting said scale platform against gravity, means in said housing for positioning said scale platform longitudinally relative to said approach platform while freely accommodating motion of said scale platform in a plane normal to that of said approach platform, means for sensing the position of said scale platform in said normal plane, and guide rail means extending along each side of said approach and scale platforms.

6. An article sorting assembly comprising a scale, a scale housing, an approach platform formed on said scale housing, a scale platform mounted on said housing, said platforms being substantially coplanar and downwardly inclined, guide rails along the sides of said platforms, an

article slide plate mounted on said scale housing and forming a coplanar continuation of said scale platform, and

article deflecting means on said slide plate; said article deflecting means comprises a deflector arm, means pivotally mounting said arm on said slide plate with said arm pro- :jecting upstream from the pivot means toward said scale platform, the inner side of said deflector arm being aligned with a guide rail when the arm is retracted, the free, upstream end of said deflector arm having a beveled end face forming an obtuse angle with said inner side of the arm for engaging the leading face of an article to be rejected when the arm is advanced; said deflector arm having a stop face formed thereon, and a stop member on said slide plate engaged by said stop face when the deflector arm is advanced.

7. A gravity feed scale for weighing articles of uniform width comprising a housing, longitudinally extending approach and scale platforms on said housing, said platforms being substantially coplanar and inclined downwardly from the horizontal, said platforms providing an unobstructed surface for accommodating sliding of the articles along the platforms, preload spring means connected between said housing and said scale platform, means for restraining said scale platform against longitudinal motion relative to said approach platform, while freely accommodating motion of said scale platform in a plane normal to that of said approach platform, and laterally spaced, straight guide rails adjustably mounted on said housing and extending along each side of both said approach and said scale platforms, said guide rails being spaced vertically above said platforms, the lateral spacing of said guide rails at said approach platform substantially equaling the lateral dimension of the articles for steadying the articles as they pass along said approach platform, before the articles slide along the scale platform, the lateral spacing of said guide rails at said scale platform being slightly greater than the lateral dimension of the articles, for causing articles which were steadied on said approach platform to slide along the scale platform without touching said guide rails.

8. A non-stop gravity slide assembly for sorting articles by weight comprising a scale housing, a scale platform having a runner, said runner having a smooth, article supporting upper surface for accommodating free, unobstructed sliding of articles onto, along and off the runner; spring means supporting said scale platform on said scale housing, said spring means comprising upper and lower cantilever springs disposed below said runner, said cantilever springs having their fixed ends mounted on said scale housing and their other ends connected to said scale platform for restraining said platform against movement in the plane of the motion of articles sliding along said upper runner surface while freely accommodating motion of said scale in a direction normal to said plane, said spring means also comprising preload spring means connected between said scale housing and said platform for urging said platform upward, stop means between said housing and platform for arresting upward movement of said platform, the article supporting surface of said runner and said cantilever springs being substantially parallel when said scale platform is undeflected and with said stop means in engagement; a slide reject plate having an article receiving portion forming a longitudinally extending, flat article receiving surface, said surface substantially formmg a smooth continuation of the upper surface of said scale platform runner; and article deflecting means at said slide reject plate; said scale platform runner and the flat article receiving surface of said slide reject plate being inclined longitudinally downwardly for free, unobstructed gravity feed of articles along the scale platform runner and the slide reject plate.

9. non-stop gravity slide assembly for sorting articles by weight comprising a scale housing, an approach platfor-In at the upper portion of said scale housing, a scale platform having a runner, said runner having a smooth, artlcle supporting upper surface for accommodating free, unobstructed sliding of articles onto, along and off the runner; means supporting said scale platform on said scale housing for restraining said platform against movement in the plane of the motion of articles sliding along said upper runner surface while freely accommodating motlon of said scale in a direction normal to said plane, said platform supporting means also comprising preload spring means connected between said scale housing and said platform for urging said platform upward, stop means between said housing and platform for arresting upward movement of said platform, the article supporting surface of said runner substantially forming a continuation of said approach platform when said scale platform is undeflected and with said stop means in engagement; a slide reject plate having an article receiving portion forming a longitudinally extending, fiat article receiving surface, said surface substantially forming a smooth continuation of the upper surface of said scale platform runner; and article deflecting means at said slide reject plate; said approach platform, said scale platform runner and the fiat article rece vlng surface of said slide reject plate being inclined longitudinally downwardly for free, unobstructed gravity feed of articles along the approach platform, the scale platform runner and the slide reject plate.

10. A checkweigher comprising: a support; a weighing platform having a sloping an'd unobstructed article supporting surface arranged at such an angle to the horizontal that an article to be weighed will slide thereover and therefrom under the influence of gravity; cantilever spring means mounted on said support and supporting said platform for weighing movement in a direction perpendicular to said sloping surface; said spring means comprising at least one resiliently flexible arm extending substantially parallel to said sloping surface; and means responsive to relative movement between said platform and support for determining whether or not an article on said platform is of predetermined weight.

11. A checkweigher as defined in claim 10 wherein said spring means comprises a pair of said resiliently flexible arms arranged in parallel relation in a vertical plane, one end of each arm being secured to said support and the other end of each being fixed relative to said platform.

12. A checkweigher as defined in claim 10 wherein said support comprises a movable frame; a base structure; and means mounting said frame on said base structure for angular adjustment in a vertical plane whereby to change the angle of slope of said surface.

(References on following page) 11 12 References Cited 3,080,936 3/ 196 3 Sher 177229 2,697,595 12/1954 Walter 177-229 UNITED STATES PATENTS 1,729,991 10/1929 Bond 177-53 1,712,700 5/1929 Harden'bergh 209-121 1,791,096 2/1931 Humphrey 209-421 2,003,722 6/1935 Powell 209-121 5 2,998,117 8/1961 Newburn -1 198-31 2,364,832 12/1944 Weckerly 209-121 542 090 2 1951 Lorenz 209 .74 ROBERT S. WARD, JR., Primary Examiner. 2,860,847 11/1958 Willbrandt 17752 2,962,166 11/1960 Miles 209 121 US 3.017.026 1/1962 Thompson 209-121 10 17750', 52, 16 1, 16 8, 229, 255 

1. AN ARTICLE SORTING ASSEMBLY COMPRISING A BASE, A SCALE HOUSING, AN APPROACH PLATFORM ON THE UPPER PORTION OF SAID SCALE HOUSING, A SCALE PLATFORM, A GENERALLY TRIANGULAR PRELOAD SPRING, MEANS MOUNTING THE BASE OF SAID PRELOAD SPRING IN SAID SCALE HOUSING, MEANS FOR SUPPORTING SAID SCALE PLATFORM IN THE APEX OF SAID PRELOAD SPRING, SCALE PLATFORM LOCATING MEANS COMPRISING UPPER AND LOWER CANTILEVER SPRINGS BEING REGIDLY MOUNTED IN SAID SCALE HOUSING AND WITH THE SCALE PLATFORM BEING RIGIDLY CONNECTED TO THE OUTER ENDS OF SAID CANTILEVER SPRINGS, SAID SCALE PLATFORM COMPRISING A RUNNER PLATE DISPOSED IN THE MIDPLANE OF SAID APPROACH PLATFORM AND WITH THE UPPER EDGE OF SAID RUNNER PLATE SUBSTANTIALLY FORMING A CONTINUATION OF SAID APPROACH PLATFORM, GUIDE RAILS AT EACH SIDE OF SAID PLATFORMS, A SLIDE PLATE RIGIDLY MOUNTED ON SCALE HOUSING AND LYING SUBSTANTIALLY IN THE PLANE OF SAID PLATFORMS, SAID SLIDE PLATE BEING NOTCHED TO RECEIVE SAID SCALE PLATFORM RUNNER PLATE, ARTICLE DEFLECTING MEANS ON SAID SLIDE PLATE, AND MEANS FOR PIVOTALLY MOUNTING SAID SCALE HOUSING ON SAID BASE. 